The high-lift low pressure turbine blade profile incidence characteristics under low Reynolds number were investigated.The modification used recessed U-grooves to improve the profiles’ incidence margin.The numerical simulations suggest that compared with high incidence flow condition

lower incidence does not induce large separation which appears on the suction surface of the profile and hence lessens profile loss.The recessed U-grooves delay the separation location

accelerate reattach location

decrease the turbulent wetted area

thereby the separation bubble is suppressed and the profile loss decreases.Whether or not the recessed U-grooves can improve the incidence margin is related to the depth and location of the U-grooves.With±15 incidence degrees

the U-grooves located in 72% axial chord length showed lower profile loss

and when the depth was 0.40mm the profile loss was the lowest.